Updated: A number of providers don't accept transfers in from previous
years Isas. We name a few of the best accounts without this restriction

It has been a disappointing start to "Isa season", when providers launch new rates before the end of the tax year to lure in potential customers ahead of the April 5 deadline for using this year's £5,760 cash Isa.

Competition between banks and building socities has been weak and rates have not dramatically improved, as they often do in March.

It can be particularly frustrating for those with Isas from previous years who wish to move the money to a better rate. They are tempted by today's headline rates which, after careful inspection, do not accept transfers in.

The reason why providers do this is to restrict the influx of money that would flood in if they offer a good rate. Often, especially on variable accounts, they just want new customers rather than attracting lots of new money.

Three of the top variable rate cash Isas on the market at the moment do not allow transfers in, including Earl Shilton's 90 Days Notice cash Isa (paying the top rate of 1.8pc), Stafford Railway Building Society's Cash Isa and Nationwide's Flexclusive Isa.

Here, we give our list of the top paying Isas that do accept transfers.

It is worth noting that some providers will charge interest penalties for transferring money out to a new Isa, so check this first.

Variable: Santander will increase the rate on its Direct Isa Saver to 1.6pc on Monday (March 17). The minimum £500 to open an account shouldn't affect most transfer in customers.

Variable: Furness Building Society's 'Cash Isa 90 Issue 2' pays 1.6-1.8pc and accepts transfers in. The account requires a minimum investment of £1,000 but pays tiered rates according to how much you pay in. The building society pays 1.6pc for balances between £1,000 to £3,000, 1.7pc on balances between £3,001 to £9,000 and 1.8pc on £9,001 and over.

Savers must give 90 days notice if they wish to make a withdrawal, otherwise they will face 90 days' loss of interest on the amount withdrawn.

Fixed: Santander has launched a highly competitivetwo-year fix, paying 2.3pc to those who are existing 123 current account or credit card customers, or 2pc to those who aren't. Withdrawing money early invokes a penalty worth 120 days' interest.

Fixed: Two banks offer a little more than Santander's standard 2pc rate over two years. Britannia's two-year fixed rate cash Isa pays 2.05pc and requires a minimum deposit of £5,760 – the maximum Isa allowance, or £1 if transferring in previous Isas. Withdrawals are allowed but incur 180 days' loss of interest. But our prefered two-year deal is Halifax's two-year Isa. It is also 2.05pc but you get entered each month in its monthly £100,000 Prize Draw.